Recognising the role of ruderal species in restoration of degraded lands.

Ruderal plants are an important component of plant communities that develop on the range of anthropogenically degraded lands. Yet they were highly neglected and not recognised as desirable for restoration purposes. The aim of this study was to analyse the potential for using ruderal species in restoration processes and to identify preliminary criteria for species selection that could be included in ecological restoration of degraded man-made habitats under future conditions of increased human disturbance and climate changes. The desirable characteristics of the species depend primarily on the type of habitat to be restored, with plant height, specific leaf area, rooting depth and seed characteristics being the most important traits. The recognised ecosystem services of the species analysed show that the provisioning and regulating services are well represented, particularly erosion control, pollination, phytoremediation and other soil quality improvements. Most of the dominant and diagnostic ruderal species from the man-made habitats of the north-western Balkan Peninsula are sensitive to climate change and their potential distribution range is expected to decrease at the European scale. Higher certain ecological indicator values, as well as values for disturbance severity, frequency and soil disturbance indices were found for species that are expected to increase their range. Ruderal species are becoming increasingly important for restoration purposes, as the focus shifts to the significance of early successional species. The inclusion of ruderal species in the restoration of degraded sites should be based on criteria such as: non-invasiveness, plant traits favourable for colonisation (height, SLA, seed traits, rooting depth), values of ecological and disturbance indices, provision of ecosystem services, and change of distribution range under changing climate conditions.

Thallium hyperaccumulation status of the violets of the Allchar arsenic-thallium deposit (North Macedonia) confirmed through synchrotron µXRF imaging.

The abandoned Allchar Mine in the Republic of North Macedonia is a globally unique deposit with the highest known grades of thallium (Tl) and arsenic (As) mineralization. We aimed to determine the distribution of As and Tl in whole dehydrated shoots of the three Viola taxa using synchrotron micro-X-ray fluorescence analysis. Additionally, soil and plant organ samples were collected from all three Viola taxa at the Allchar site and analysed using inductively coupled plasma-atomic emission spectrometry. Concentrations of Tl were extremely high in all three Viola taxa (up to 58 900 mg kg-1), but concentrations of As were highly variable with V. tricolor subsp. macedonica and V. allchariensis having low As (up to 20.2 and 26.3 mg kg-1, respectively) and V. arsenica having the highest concentrations (up to 381 mg kg-1). The extremely high Tl in all three species is endogenous and not a result of contamination. Arsenic in V. tricolor subsp. macedonica and V. allcharensis is strongly affected by contamination, but not in V. arsenica where it appears to be endogenous. The pattern of As enrichment in V. arsenica is very unusual and coincides with Ca-oxalate deposits and Br hotspots. The results of this study could form the basis for more detailed investigations under controlled conditions, including plant dosing experiments.

Analysis of the Qualitative and Quantitative Content of the Phenolic Compounds of Selected Moss Species under NaCl Stress.

The response to salt stress analysed by quantitative and qualitative analyses in three selected moss species was studied. Non-halophytic funaroid Physcomitrium patens and two halophytic mosses, funaroid Entosthodon hungaricus and pottioid Hennediella heimii were exposed to salt stress under controlled in vitro conditions. The results clearly showed various phenolics to be present and included to some extent as a non-enzymatic component of oxidative, i.e., salt stress. The common pattern of responses characteristic of phenolic compounds was not present in these moss species, but in all three species the role of phenolics to stress tolerance was documented. The phenolic p-coumaric acid detected in all three species is assumed to be a common phenolic included in the antioxidative response and salt-stress tolerance. Although the stress response in each species also included other phenolics, the mechanisms were different, and also dependent on the stress intensity and duration.

Strategies of accumulation of potentially toxic elements in Minuartia recurva and M. bulgarica.

The aim of this study was to determine the concentrations of potentially toxic elements in soil samples and plant tissues of Minuartia recurva and M. bulgarica, predominantly or exclusively calcifuge species. Biological concentration (BCs) and translocation factors (TFs) were used to evaluate their accumulation potential. Considerable differences were observed between M. recurva and M. bulgarica assessions in terms of accumulation strategies of potentially toxic elements (PTEs). In M. recurva, most of the elements analyzed (Mn, Cu, Zn, Cd, and Co) were transported to the shoot, whereas in M. bulgarica, these elements remained predominantly in the roots. The Cu concentrations in the shoot samples of M. recurva from an abandoned iron-copper mine at Mt. Kopaonik were clearly above the notional hyperaccumulation threshold, characterizing this species as a possible Cu hyperaccumulator. Additionally, strong accumulation potential for Cr, Ni, Zn, Pb, and Cd was observed in M. recurva assessions, but without significant accumulation due to the low concentrations of these elements in the soils. The strong accumulation capacity and the different strategies in tolerance to PTEs indicate a potential of the two species for an application in phytoremediation: M. recurva for phytoextraction and M. bulgarica for phytostabilization.

Influence of Habitat Types on Diversity and Species Composition of Urban Flora-A Case Study in Serbia.

The aim of this study was to investigate the floristic composition and diversity of seven urban habitat types in 24 Serbian cities with different climatic affiliation. In each of the 24 cities, we selected 1 ha plots representing a habitat from one of the following groups: square, boulevard, residential area with compact and with open building pattern, city park, and sites with early and mid-succession vegetation stages. All vascular plant species that occur spontaneously in these plots were observed. Data on the main climatic characteristics were collected for each plot, and data on the life forms were obtained for each species recorded. Diagnostic species were identified for each habitat type analyzed, and alpha, beta and gamma diversity were calculated. A total of 674 taxa were recorded in the studied area. Significant differences were observed in habitats by diagnostic species and by life form representation. The lowest alpha and gamma diversity and the dominance of therophytes were observed in habitat types with intensive anthropogenic impact, whereas the highest number was recorded in mid-successional sites and residential areas with a compact building pattern. The analysis showed that habitat type influences species composition much more than climate.

Brassica Species in Phytoextractions: Real Potentials and Challenges.

The genus Brassica is recognized for including species with phytoaccumulation potential and a large amount of research has been carried out in this area under a variety of conditions, from laboratory experiments to field trials, with spiked or naturally contaminated soils, using one- or multi-element contaminated soil, generating various and sometimes contradictory results with limited practical applications. To date, the actual field potential of Brassica species and the feasibility of a complete phytoextraction process have not been fully evaluated. Therefore, the aim of this study was to summarize the results of the experiments that have been performed with a view to analyzing real potentials and limitations. The reduced biomass and low metal mobility in the soil have been addressed by the development of chemically or biologically assisted phytoremediation technologies, the use of soil amendments, and the application of crop management strategies. Certain issues, such as the fate of harvested biomass or the performance of species in multi-metal-contaminated soils, remain to be solved by future research. Potential improvements to current experimental settings include testing species grown to full maturity, using a greater amount of soil in experiments, conducting more trials under real field conditions, developing improved crop management systems, and optimizing solutions for harvested biomass disposal.

Plantago subulata as indicator of potentially toxic elements in the substrate.

Plantago subulata is a facultative serpentinophyte, with predominantly ultramafic distribution in Serbia and Montenegro. The plant samples were collected from ultramafic and non-ultramafic substrate, including two abandoned mining sites, with the aim to assess the accumulation potential of this species. The samples were collected from 10 sites in Serbia and Montenegro and element concentrations in plants and soils were determined. Particularly high concentrations of Fe, Cu, Mn, Zn, and Cd were found in the soil and plant samples from an abandoned iron mining site, Mt. Kopaonik, Suvo Rudiste. The concentrations of Ni, Cr, Fe, Co, and Cd were statistically different between soil and plant samples from ultramafic and non-ultramafic bedrock. Considering the fact that concentrations of Zn, Ni, and Cr in roots and shoots were positively correlated with their respective contents in the soil, i.e., the chemical composition of the plant and soil samples reflected the characteristics of the substrate, and for most of the elements analyzed, P. subulata acted as indicator species. For Cd and Pb, only the root concentrations were positively correlated with soil content, indicating exclusion and root sequestration as the main tolerance strategies for these elements. Although below the hyperaccumulation threshold, a strong accumulation capacity of P. subulata was found for Ni and Cu.

Evaluation of Salix alba, Juglans regia and Populus nigra as biomonitors of PTEs in the riparian soils of the Sava River.

A large number of human activities result in the release of potentially toxic elements (PTEs) into the environment, which could lead to the degradation of riparian areas. This study aimed to evaluate the potential of Salix alba, Juglans regia and Populus nigra for the biomonitoring of PTEs in the riparian soils of the Sava River. Levels of seven PTEs (As, Cd, Cr, Cu, Ni, Pb and Zn) were measured in the soils, roots and leaves of plants at selected sampling sites and evaluated according to bioaccumulation and translocation factors. The obtained results showed that in riparian soils, As, Cr, Cu, Ni and Zn were at levels considered to be critical for plants. The levels of As, Cd, Cr, Ni and Zn measured in roots of Salix alba and As, Cr, Ni and Zn in its leaves were toxic for plant tissue. Toxic levels of Cr were also measured in the roots of Juglans regia and As in its leaves, as well as As and Cr in the roots of Populus nigra, and Zn in its leaves. Bioconcentration and translocation factors showed that S. alba and P. nigra have potential for the phytoextraction of Zn and Cd, while J. regia has potential for the phytoextraction of As. In terms of phytostabilization potential, S. alba proved to be good for the phytostabilization of Cd and Cu, and J. regia for the phytostabilization of Cr, As, Ni and Pb, while P. nigra showed potential for the phytostabilization of Cr, Ni, Pb and Cu.

Accumulation of trace elements in Tussilago farfara colonizing post-flotation tailing sites in Serbia.

The purpose of this study was to examine the accumulation potential of spontaneously developed Tussilago farfara populations colonizing sites with different levels of anthropogenic pollution. Physical characteristics of the soil are presented, together with the concentrations of macroelements and microelements (Ca, Mg, Fe, S, Al, Pb, Zn, Cu, Cd, Mn, As, Sb, Ag, Ti, and Sr) in both soil and plants. The biological concentration, accumulation, and translocation factors were used to assess the potential for heavy metal accumulation. Considerable differences were found among assessions from unevenly contaminated habitats, particularly in comparison with an unpolluted site. In line with the ore's characteristics, substrate samples from polluted sites were heavily contaminated with Pb, Zn, As, and Sb. Increased levels of microelements were also detected in plant samples from flotation tailings. Despite active absorption of Zn, Cu, Cd, Mn, and Sr by the plants from mining sites, the detected quantities of these elements in all samples were below the hyperaccumulation threshold. However, the obtained results indicate that the use of T. farfara from such sites in traditional medicine could pose a risk to human health due to accumulation of several toxic elements in the plant's aboveground tissues. Additionally, as a successful primary colonizer and stabilizer of technogenic substrates, T. farfara has an important role in the initial phases of revegetation of highly contaminated sites.

The potential of elm trees (Ulmus glabra Huds.) for the phytostabilisation of potentially toxic elements in the riparian zone of the Sava River.

The use of trees to immobilise potentially toxic elements (PTEs) is a low-cost and effective method of soil remediation. Thus, the objective of this study was to assess the content of total and bioavailable As, Cd, Cr, Cu, Ni, Pb and Zn in soil samples, as well as their levels in the roots and leaves of elm (Ulmus glabra Huds.) in order to evaluate its potential for the phytostabilisation of PTEs in the riparian zone of the Sava River. Analysis of soils showed that the availability of PTEs ranged from low to medium, while the pollution load index (PLI) and potential ecological risk index (RI) showed that the examined soil fell into the category of uncontaminated to moderately contaminated, as well as into the category of low risk of PTEs contamination. However, the levels of Cr, Cu and Ni in soils were above the critical range for plants. The content of As and Cr measured in roots and leaves was in the toxic range for plants, while the content of Cd and Ni was elevated but not in the toxic range. Bioaccumulation (BCF) and translocation (TF) factors indicated that U. glabra is suitable for the phytostabilisation of As, Cu, Cr, Ni and Pb. Additionally, this species displayed the ability to transport most of the acquired Cu and Zn to the leaves. Correlation analysis showed that PTE content in U. glabra roots was significantly positively correlated to their respective levels in soil (total and DTPA-extractable), except for Cu, indicating that PTE levels in soil strongly influence those in plants. This research into a successful phytoremediating species provides new possibilities when selecting PTE-tolerant native trees in riparian zones of large regional rivers such as the Sava.

Micro-edaphic factors affect intra-specific variations in trace element profiles of Noccaea praecox on ultramafic soils.

The aim of this study was to compare trace element profiles of Noccaea praecox (Wulfen) F. K. Mey. growing on ultramafic soils in different habitat types and to observe differences in uptake and translocation of trace elements. Physico-chemical characteristics of the soil and concentrations of P2O5, K2O, Ca, Fe, Mn, Zn, Cu, Ni, Cr, Pb, Cd, and Co in plant samples were presented. Biological concentration, accumulation, and translocation factors were calculated to estimate accumulation potential of different N. praecox accessions. All of the studied accessions were Ni hyperaccumulators (with shoot concentrations up to 14,593 mg kg-1), but with notable differences in accumulation and translocation rates. Significant differences in accumulation and translocation patterns of trace elements were observed among accessions from habitats characterized as serpentine steppes on dry, shallow soils in contrast to the accessions from habitats with higher soil moisture, and higher content of organic matter.

Metal accumulation in populations of Calamagrostis epigejos (L.) Roth from diverse anthropogenically degraded sites (SE Europe, Serbia).

Heavy metal accumulation is recognized as a very important global pollution problem in the last decades. Plant species have been recognized as natural bioindicators of environmental pollution, especially the amount of heavy metals in soils. Moreover, only a limited number of plant species can survive in highly contaminated soils. It is also known that metal accumulation can vary greatly among different populations of the same species. This study examines the chemical composition and accumulation potential of the expansive clonal grass Calamagrostis epigejos at five localities exposed to different levels of anthropogenic pressure. Considerable differences were observed between uptake, translocation, and accumulation of total and available heavy metals, such differences corresponding to soil physico-chemical characteristics and the level of site pollution. The results indicate that Calamagrostis epigejos uptakes a significant portion of the available fraction of heavy metals in the soil and stores it in the roots, thereby exhibiting a certain potential for metal phytostabilization.

Strategies of heavy metal uptake by three Armeria species growing on different geological substrates in Serbia.

This study surveyed three species of the genus Armeria Willd. from five ultramafic outcrops, two non-ultramafic (schist) soils, and one tailing heap of an abandoned iron-copper mine from Serbia. Similarities and differences among the three Armeria species growing on different geological substrates in the ability to control uptake and translocate nine metals were examined. Chemical characteristics of the soil and plant samples (concentrations of P2O5, K2O, Ca, Fe, Mn, Ni, Zn, Cu, Cr, Co, Cd, and Pb) are presented. In order to assess accumulative potential of these three Armeria species, biological concentration, accumulation, as well as translocation factors were used. Three investigated Armeria species growing on eight different localities showed large differences in heavy metal uptake, translocation, and accumulation. The differences were present among the plant samples of the same species and even more among three different Armeria species and were primarily the result of the different contents of available heavy metals in the investigated soils. Additionally, differences might be the consequence of diverse responses and possible presence of supplementary resistance mechanisms in the plants from the ultramafic soils. None of the three Armeria species showed shoot hyperaccumulative potential for any of the investigated heavy metals and they could be considered as root accumulators, considering their potential to accumulate medium to large amounts of Zn (BCF up to 134), Cr (BCF up to 148), and Cd (BCF up to 9) in their roots.

Association of TP53 codon 72 polymorphism with susceptibility to ovarian carcinomas in Serbian women.

OBJECTIVES: Finding a potential genetic factor associated with a deadly disease, such as ovarian carcinoma, is of particular importance. The aim of this study was to examine the role of the TP53 codon 72 polymorphism in ovarian carcinoma development in Serbian women. STUDY DESIGN: 47 wild-type TP53 gene ovarian carcinoma samples and 70 cervical smears from gynecologically healthy women were analyzed. DNA was extracted by a salting-out procedure. Codon 72 polymorphism was assessed by PCR-RFLP method. χ(2), Fisher exact test and odds ratio were used for statistical analysis. RESULTS: The distribution of Arg/Arg, Arg/Pro and Pro/Pro genotypes of codon 72 of the TP53 gene was: 46.8%, 46.8% and 6.4%, respectively in the ovarian carcinomas and 64.3%, 31.4% and 4.3%, respectively in the control group. We observed an increased risk for the development of ovarian carcinoma for Pro homozygotes in relation to heterozygotes plus Arg homozygotes (OR=1.52; 95% CI 0.29-7.89) and a higher one for Pro/Pro plus Arg/Pro genotype in relation to Arg homozygotes (OR=2.04; 95% CI 0.96-4.34). CONCLUSION: The results showed no association between codon 72 TP53 gene polymorphism and risk for development of ovarian carcinoma in Serbian women. However, this observation requires further analysis of a larger case-control study group.

Detection and genotyping of human papillomaviruses and their role in the development of ovarian carcinomas.

PURPOSE: The objective of this study was to investigate the presence of human papillomavirus (HPV) infection in ovarian carcinoma samples from Serbian women and correlate them with clinicopathological characteristics of disease and patients' characteristics. METHODS: Fifty-four ovarian carcinoma patients were included in the study. DNA was isolated by salting out method from tumor tissue obtained after surgical treatment. Presence of HPV infection was detected through polymerase chain reaction amplification of a 150-bp fragment of L1 viral gene by GP5+/GP6+ primers. HPV genotyping was performed by DNA sequencing. RESULTS: HPV DNA was present in 4/54 (7.4 %) ovarian carcinomas. All HPV-positive tumors contained high-risk HPV16 type. HPV infection was more common in advanced opposite to localized disease. The median age of diagnosis of disease varied from 57 years for patients with HPV infection to 59 years for patients without HPV infection. CONCLUSIONS: Our results indicate that HPV infection may play a limited role in ovarian carcinogenesis.

Picolinate ruthenium(II)-arene complex with in vitro antiproliferative and antimetastatic properties: comparison to a series of ruthenium(II)-arene complexes with similar structure.

In our previous study, ruthenium(II)-p-cymene complexes of general formula [(η(6)-p-cymene)Ru(L)Cl2], L: 3-acetylpyridine (1), 2-amino-5-chloropyridine (2); and [(η(6)-p-cymene)Ru(HL)Cl], HL: 2,3-pyridinedicarboxylic acid (3), 2,4-pyridinedicarboxylic acid (4), revealed low antiproliferative activity, except complex [(η(6)-p-cymene)RuCl(picolinic acid)]·H(2)O (5) which exhibited IC(50) around 80 µM. In this study we further investigated in vitro potential of antimetastatic action of ruthenium complexes on HeLa and two endothelial cell lines. Comparison of structure and activity of five complexes indicated heterogenic mode of activity, with regard to the potential of antimetastatic and antiproliferative effect. Replacement of substituted pyridine ligand with picolinic acid (complex 5) around Ru(II) center contributed to complex cytotoxicity and ruthenium DNA binding affinity. Analysis of ruthenium(II) accumulation in DNA and protein fractions of HeLa cells, using ICP-OES revealed significantly higher content of complex 5 in DNA fraction in comparison to the other tested compounds. It also altered cell cycle progression, affected expression of DNA repair enzymes ERCC1 and MSH2, and showed enhanced activity in combination with 3-aminobenzamide. Regardless of their effect on cell growth, Ru(II) complexes exerted antimetastatic effect on several tumor cell lines in vitro, achieved mostly by the effect on cell adhesion, migration and angiogenesis, while picolinate ruthenium(II)-arene additionally exerted inhibitory effect on extracellular matrix degradation.

Association between methylenetetrahydrofolate reductase polymorphism C677T and risk of chronic myeloid leukemia in Serbian population.

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme regulating the intracellular folate metabolism which plays an important role in carcinogenesis through DNA methylation and nucleotide synthesis. The common MTHFR single nucleotide polymorphism C677T has been reported to be associated with reduced enzymatic activity. In order to investigate the influence of this polymorphism on the risk of chronic myeloid leukemia (CML), we performed a case-control study in a Serbian population of 52 patients with CML and 53 healthy control subjects. MTHFR C677T polymorphism genotyping was assessed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The results demonstrated no statistical difference in MTHFR 677 frequency distribution between patient and control groups. Our findings suggest that MTHFR 677 gene variants have no significant influence on the susceptibility to CML in a Serbian population.